The National Institute on Aging is seeking minimally perturbing techniques for collecting blood from mice, rats, and other laboratory animals several times a day in sufficient quantities to measure hormone levels and other circulating factors in young and old animals over the course of long-term experiments. Current blood collection techniques cause pain and stress, and require anesthesia, or are unsuitable for long-terms repeated experiments. No instrument is available for undisturbed and painless blood collection from unanesthetized and unrestrained laboratory rodents 3-4 times a day over long-term experiments. To address this need, Physical Optics Corporation proposes to design, develop, and fabricate a new portable Laser Lancing Device (LLD) for painless and rapid (1-1.5 min.) collection of serial blood samples from the tails of unanesthetized rodents. The main goal of this Phase II project is to develop a complete engineering LLD prototype ready for testing and validation in research laboratories and veterinary clinics. The new LLD blood collecting system will be a technological breakthrough in laboratory animal science, and especially in animal studies that require minimally perturbing blood sampling. Because of the unique properties of the LLD and its improved treatment of laboratory animals, it will also have wide application in animal clinics, animal shelters, and veterinary medicine. This Phase II effort to develop an LLD will include the following: optimizing the laser diode irradiation regime based on an improved optical projection system that will allow shorter pulses and pulse trains, to diminish collateral thermal damage; designing and fabricating inflatable heating cuffs that will be easy to operate and minimally perturbing to the animals; and integrating and packaging the complete engineering LLD prototype for testing and validation in research laboratories and veterinary clinics. When fully developed, the LLD will be a rapid, painless, stress-free, easy-to-use device for collecting serial blood samples from the tails of unanesthetized mice and rats.